This isn't a regular sibling fallout. It is a deep-rooted fracture filled with anger, resentment and a total loss of trust.

And much of it has played out in public.

The Prince of Wales remains in no mood to forgive and forget. The hurt he feels lingers.

"William is very stubborn," a family friend told the BBC. "To feel cheated by your own brother has been painful. He can't just put it behind him."

But in his interview with the BBC last year, Harry offered a different view.

"I would love reconciliation with my family. There's no point in continuing to fight any more."

The problem for Prince William now is proximity. Harry will be in the UK within two weeks, probably a short drive away from Windsor where William's family lives.

There will be pressure on the elder brother to take the lead, ease the pain and just make up with Harry now the siblings will be living in the same country.

"I think William doesn't care about the pressure to reconcile," said royal author, Valentine Low. "If he doesn't want to reconcile with his brother because of the things he's done, the wrongs that he feels Harry's done to him, he's not going to reconcile. But it does improve the chances I think."

The Prince of Wales will prioritise his public work in the coming months and try not to get drawn into the drama around the UK return of the Duke and Duchess of Sussex.

Several people from organisations who have worked with Prince William told BBC News of their desire to support William and help avoid Harry and Meghan becoming a distraction.

One source, who has worked on charity projects with the Royal Family, described wanting to protect the future King.

"This is a hard situation for him full of emotion and anger and we will support him," the source said. "It is really important for me to ensure that any work we do with William will be focused on making a positive change and won't be affected by the Harry and Meghan drama."

Kensington Palace has been tight-lipped since news of the Sussexes' return. There has been no official comment and their team would not be drawn into conversations about Harry and Meghan.

Their strategy is clearly to just carry on with royal business.

Over the next few months, the Prince of Wales has a number of projects with personal significance.

In November, he will travel to Mumbai in India for his environmental Earthshot Prize Award.

There is also a major project around mental health that will be launched in the coming weeks.

And in September comes a big moment in the life of any family when Prince George starts senior school. The media management of that moment at Eton College in Berkshire will be carefully choreographed. His parents will be fiercely protective of this significant milestone for their 13-year-old son and won't want him exposed to any family upset and drama.

Underlying so much of their relationship now is the life experience both brothers have had over the past six years since Harry moved away.

They have grown apart.

William has faced the life-changing experience of supporting his wife through her cancer treatment while watching his father fight his own battle with the disease.

He is a different brother from the one Harry left behind six years ago.

And a brother who is not in the mood to forgive... for now.

"Having Harry nearby won't change the mood," said a former colleague of the heir to the throne. "William will need time."